Considerable problems can arise with the use of conventional solvents in many types of chemical reactions including fluorination reactions. One problem often encountered is that of solvent recovery, which can often prove difficult and lead to solvent disposal problems. In addition, solvent consumption itself may be undesirably large and the solvent may present an explosion hazard. Thus, there exists a need to reduce the amount of solvent used in many reactions.
Surprisingly and beneficially, we have found that fluorination reactions carried out in the presence of a perfluorocarbon (PFC) fluid can require less solvent than would otherwise, i.e. conventionally, be used for the reaction to proceed efficiently.
Perfluorocarbons are largely chemically inert, and are generally regarded as largely immiscible with most organic solvents, although published data is sparse. Miscibility with CFCl.sub.2 CF.sub.2 Cl and some low molecular-weight hydrocarbons has been recorded, together with the fascinating solubility of gases such as oxygen, carbon dioxide and chlorine. Saturated perfluorocarbons (PFCs), e.g. perfluoroperhydrophenanthrene 1 shown in FIG. 1, are now industrially available over a wide boiling-point range.